A case-control study was used to test this hypothesis. The case group consisted of 47 adolescent suicide victims. The psychiatric inpatient control groups were 47 suicide attempters and 47 never-suicidal psychiatric controls who were frequency- matched to the suicide victims on age, gender, and county of origin. The cases were a consecutive community sample; the inpatients were drawn from a university psychiatric hospital. The main outcome measure was the odds of the presence of guns in the home of suicide victims (cases) relative to controls. The findings show that guns were twice as likely to be found in the homes of suicide victims as in the homes of attempters or psychiatric controls. Handguns were not associated with suicide to any statistically significantly greater extent than long guns. There was no difference in the methods of storage of firearms among the three groups, so that even guns stored locked or separate from ammunition were associated with suicide by firearms. The study concludes that the availability of guns in the home, independent of firearms type or method of storage, appears to increase the risk for suicide among adolescents. Physicians should make a clear and firm recommendation that firearms be removed from the homes of adolescents deemed to be at risk of suicide. 4 tables and 27 references